Problem: Simplify the following expression: $x = \dfrac{t}{4} + \dfrac{7t}{2}$
Explanation: In order to add expressions, they must have a common denominator. The smallest common denominator is the least common multiple of $4$ and $2$ $\lcm(4, 2) = 4$ $ x = \dfrac{1}{1} \cdot \dfrac{t}{4} + \dfrac{2}{2} \cdot \dfrac{7t}{2} $ $x = \dfrac{t}{4} + \dfrac{14t}{4}$ $x = \dfrac{t +14t}{4}$ $x = \dfrac{15t}{4}$